Over the past few years, increasing numbers of women have elected to deliver outside the hospital in maternity centers or at home. The objective of this study is to evaluate the physical safety of an "out-of-hospital" maternity center. Two questions are addressed by this epidemiological prospective non-concurrent study: 1) Do maternal and neonatal outcomes of two populations comparable on sociodemographic and medical-obstetric risk differ in two institutions with different approaches to maternity care? 2) Does the process of transfer from one institution to another involve increases risk to sick pregnant women and newborns? The study populations, selected from Booth Maternity Center and Thomas Jefferson University Hospital, both located in Philadelphia, Pennsylvania, will be matched by distribution for the investigation of the first question and by pair for the investigation of the second. Matching variables will be: race, maternal age, education, gravidity, and previous pregnancy loss. Pregnancy outcomes process of care, medical-obstetric risk and sociodemographic characteristics will be analyzed by univariate and multivariate statistical techniques.